## Energy Levels [ENDORSED]

Eryn Wilkinson 3H
Posts: 20
Joined: Fri Sep 29, 2017 7:07 am

### Energy Levels

Hi y'all, so on ch. 1 question 15 it asks you to find the initial and final energy levels of the hydrogen, but it expects you to know that hydrogen starts at n1=1. Is that because hydrogen has one electron so it automatically starts in the first energy level? How would you find out what energy level it starts at if it was a different element?

Ryan Sydney Beyer 2B
Posts: 82
Joined: Fri Sep 29, 2017 7:07 am
Been upvoted: 1 time

### Re: Energy Levels  [ENDORSED]

The question states that the emission given off is in the ultraviolet so we know that it is in the Lyman Series.
From this we know that n2 = 1. I think any problem has to give us some clue as to which energy level it is referring to or else we would have to resort to guess and check methods.

From there we use $E=hc/\lambda$ and $E = -hR/(n^2)$ to solve for the energy of the ultraviolet light and the energy of the final energy state. Then we subtract the two and rearrange $E = -hR/(n^2)$ to look like $n = \sqrt{-hR/E}$ and then we can solve for n1.